I'm heading down Apr. 14. The flats around Ambergris and Caulker Caye are muddy and generally not suitable for wading. If you're taking a sailboat out around the islands, you should find hard sand flats that are wadeable. As much as you might want your new switch rod, 9' 4-piece rods are far more practical for travel. A 6 or 7 wt is good for the bonefish -they are pretty small, 1-3 lbs. And 8 wt for permit and a 10 for baby tarpon and good sized snook, also barracuda.
Buy a couple 10' 10# bonefish leaders and a spool of 10# clear stiff tippet. I know the bones are small, but I seem to break fish off on the strike using 8#, and I use 8# tippet for big steelhead. If you target permit, you will appreciate 15# tippet. Make a simple tarpon leader of clear stiff mono (Maxima) - 3' 40#, 2' 30#, 18" 15# class section, then 18" 40# shock tippet - tarpon mouth is like heavy duty sand paper. If you set up for barracuda replace the shock tippet with 1' of wire leader. If you don't tie your own, get an assortment of basic flies from a shop that carries tropical flats flies. There is a shop on Ambergris and at Caulker, but if they aren't on your route, you should bring your own. Gotcha' and spawning shrimp in pinkish tan size 6 and 4 is good for bones. A size 2 or 4 raghead or Merkin crab in pinkish tan and brownish tan is good for permit. Toads in 2/0, black, and purple, and a black death streamer are good tarpon bait.